Form shows blank page on submit - php

Question

I have been though the other questions and and nothing seems to help me!
I managed to get a thank you message using a previous help thread but that never resulted in an email. Please help me!
Html Code
<form name="AberdaronApplication" method="post" action="submit.php">
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="ContactName">Main Contact Name</label>
<input type="text" name="ContactName" class="form-control main" id="ContactName" placeholder="Main Contact Name">
<label class="sr-only" for="FirstAddress">AddressFirstLine</label>
<input type="text" name="FirstAddress" class="form-control main" id="FirstAddress" placeholder="First Line of Address">
</div>
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="HomeNumber">Home Number</label>
<input type="tel" name="HomeNumber" class="form-control" id="HomeNumber" placeholder="Home Telephone">
<label class="sr-only" for="SecondAddress">Second Line of Address</label>
<input type="text" name="SecondAddress" class="form-control" id="SecondAddress" placeholder="Second Line of Address">
</div>
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="MobileNumber">Mobile Number</label>
<input type="tel" name="MobileNumber" class="form-control" id="MobileNumber" placeholder="Mobile Number">
<label class="sr-only" for="City">City</label>
<input type="text" name="City" class="form-control" id="City" placeholder="City">
</div>
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="Email">Email Address</label>
<input type="email" name="Email" class="form-control" id="Email" placeholder="Email Address">
<label class="sr-only" for="PostCode">Post Code</label>
<input type="text" name="PostCode" class="form-control" id="PostCode" placeholder="Post Code">
</div>
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob">dob</label>
<input type="date" name="dob" class="form-control dob" id="dob" placeholder="Date of Birth">
<label class="sr-only" for="age">Age</label>
<input type="number" name="age" class="form-control age" id="age" placeholder="Age">
<label class="sr-only" for="allergy">allergy</label>
<input type="text" name="allergy" class="form-control ale" id="allergy" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<p class="Left">Details of Attendees<br />
<small>Leave fields blank if no attendees and scroll down to Details of Accommodation</small></p>
<div class="form-group">
<label class="sr-only" for="Contact1">Attendee Name</label>
<input type="text" name="Contact1" class="form-control main" id="Contact1" placeholder="Attendee Name">
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob1">dob</label>
<input type="date" name="dob1" class="form-control dob" id="dob1" placeholder="Date of Birth">
<label class="sr-only" for="age1">age</label>
<input type="number" name="age1" class="form-control age" id="age1" placeholder="Age">
<label class="sr-only" for="allergy1">allergy</label>
<input type="text" name="allergy1" class="form-control ale" id="allergy1" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<div class="form-group">
<label class="sr-only" for="Contact2">Attendee Name</label>
<input type="text" name="Contatc2" class="form-control main" id="Contact2" placeholder="Attendee Name">
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob2">dob</label>
<input type="date" name="dob2" class="form-control dob" id="dob2" placeholder="Date of Birth">
<label class="sr-only" for="age2">age</label>
<input type="number" name="age2" class="form-control age" id="age2" placeholder="Age">
<label class="sr-only" for="allergy2">allergy</label>
<input type="text" name="allergy2" class="form-control ale" id="allergy2" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<div class="form-group">
<label class="sr-only" for="Contact3">Attendee Name</label>
<input type="text" name="Contact3" class="form-control main" id="Contact3" placeholder="Attendee Name">
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob3">dob</label>
<input type="date" name="dob3" class="form-control dob" id="dob3" placeholder="Date of Birth">
<label class="sr-only" for="age3">age</label>
<input type="number" name="age3" class="form-control age" id="age3" placeholder="Age">
<label class="sr-only" for="allergy3">allergy</label>
<input type="text" name="allergy3" class="form-control ale" id="allergy3" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<div class="form-group">
<label class="sr-only" for="Contact4">Attendee Name</label>
<input type="text" name="Contact4" class="form-control main" id="Contact4" placeholder="Attendee Name">
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob4">dob</label>
<input type="date" name="dob4" class="form-control dob" id="dob4" placeholder="Date of Birth">
<label class="sr-only" for="age4">age</label>
<input type="number" name="age4" class="form-control age" id="age4" placeholder="Age">
<label class="sr-only" for="allergy4">allergy</label>
<input type="text" name="allergy4" class="form-control ale" id="allergy4" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<div class="form-group">
<label class="sr-only" for="Contact5">Attendee Name</label>
<input type="text" name="Contact5" class="form-control main" id="Contact5" placeholder="Attendee Name">
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob5">dob</label>
<input type="date" name="dob5" class="form-control dob" id="dob5" placeholder="Date of Birth">
<label class="sr-only" for="age5">age</label>
<input type="number" name="age5" class="form-control age" id="age5" placeholder="Age">
<label class="sr-only" for="allergy5">allergy</label>
<input type="text" name="allergy5" class="form-control ale" id="allergy5" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<div class="form-group">
<label class="sr-only" for="Contact6">Attendee Name</label>
<input type="text" name="Contact6" class="form-control main" id="Contact6" placeholder="Attendee Name">
</div>
<div class="form-group">
<div class="form-inline">
<label class="sr-only" for="dob6">dob</label>
<input type="date" name="dob6" class="form-control dob" id="dob6" placeholder="Date of Birth">
<label class="sr-only" for="age6">age</label>
<input type="number" name="age6" class="form-control age" id="age6" placeholder="Age">
<label class="sr-only" for="allergy6">allergy</label>
<input type="text" name="allergy6" class="form-control ale" id="allergy6" placeholder="Allergies/Medical Info">
</div>
</div>
<br />
<p class="Left">Details of Accommodation</p>
<div class="form-group">
<select class="form-control">
<option>Camp Pod</option>
<option>Camp Tent</option>
<option>Own Tent</option>
<option>Own Caravan </option>
</select>
</div>
<input type="submit" value="submit" id="submit" class="btn btn-success">Book Place</input>
</form>
PHP Code
<?php
$ContactName = $_POST['ContactName'];
$FirstAddress = $_POST['FirstAddress'];
$SecondAddress = $_POST['SecondAddress'];
$City = $_POST['City'];
$Postcode = $_POST['Postcode'];
$HomeNumber = $_POST['HomeNumber'];
$MobileNumber = $_POST['MobileNumber'];
$Email = $_POST['Email'];
$Contact1 = $_POST['Contact1'];
$dob1 = $_POST['dob1'];
$age1 = $_POST['age1'];
$allergy1 = $_POST['allergy1'];
$Contact2 = $_POST['Contact2'];
$dob2 = $_POST['dob2'];
$age2 = $_POST['age2'];
$allergy2 = $_POST['allergy2'];
$Contact3 = $_POST['Contact3'];
$dob3 = $_POST['dob3'];
$age3 = $_POST['age3'];
$allergy3 = $_POST['allergy3'];
$Contact4 = $_POST['Contact4'];
$dob4 = $_POST['dob4'];
$age4 = $_POST['age4'];
$allergy4 = $_POST['allergy4'];
$Contact5 = $_POST['Contact5'];
$dob5 = $_POST['dob5'];
$age5 = $_POST['age5'];
$allergy5 = $_POST['allergy5'];
$Contact6 = $_POST['Contact6'];
$dob6 = $_POST['dob6'];
$age6 = $_POST['age6'];
$allergy6 = $_POST['allergy6'];
$formcontent = $ContactName . "\n" . $FirstAddress . "\n" . $SecondAddress . "\n" . $City . "\n" . $Postcode . "\n" . $HomeNumber . "\n" . $MobileNumber . "\n" . $Email . "\n" . $Contact1 . "\n" . $dob1 . "\n" . $age1 . "\n" . $allergy1 . "\n" . $Contact2 . "\n" . $dob2 . "\n" . $age2 . "\n" . $allergy2 . "\n" . $Contact3 . "\n" . $dob3 . "\n" . $age3 . "\n" . $allergy3 . "\n" . $Contact4 . "\n" . $dob4 . "\n" . $age4 . "\n" . $allergy4 . "\n" . $Contact5 . "\n" . $dob5 . "\n" . $age5 . "\n" . $allergy5 . "\n" . $Contact6 . "\n" . $dob6 . "\n" . $age6 . "\n" . $allergy6;
$to = 'myemail#me.com';
$subject = "Aberdaron Camp Booking";
$mailheader = "From:" $ContactName "\r \n";
if (isset($_POST['submit']))
{
if (mail($to, $subject, $formcontent, $mailheader))
{
echo '<p>Your message has been sent!</p>';
}
else
{
echo '<p>Something went wrong, go back and try again!</p>';
}
}
?>

Answer 1

You didn't put name="ContactName" in any of your <input type="text".... post get the input values from name and not from id put name in every of your input and select <input type="text" name="put field name here"...> and select name="name here".
your code should be something like :
<input type="number" name="age5" class="form-control age" id="age5" placeholder="Age">
and concatenate (.) line break in $formcontent like :
$formcontent = $ContactName . "\n" . $FirstAddress ."\n" . $so_on ;
Update
Expand your headers
$mailheader = "From: noreply#site.com\r\n";
$mailheader .= "MIME-Version: 1.0\r\n";
$mailheader .= "Content-Type: text/html; charset=ISO-8859-1\r\n";
$mailheader .= "X-Priority: 1\r\n";

Answer 2

Needed to add and if Server request as follows:
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$ContactName...
And adding some more concatenates
$headers = 'From: '.$ContactName."\r\n" . 'Reply-To: '.$ContactName."\r\n";
Problem solved